Since the zodiac was plotted 2,000 years ago, the earth has "preceded" - spinning and tilting like a top. While the calendar alignment with constellations may have changed over the centuries, the allure of the starry skies never does. These necklaces are nickel-free. The 14 karat gold-dipped pendants are inset with crystal accent stones to form constellations. The cable necklace is adjustable, from 16 to 18 inches.